The number of extreme downpours increased steadily between 1964 and 2013—a period when global warming also intensified, according to research published in the journal Water Resources Research.
The frequency of ‘extreme precipitation events’ increased in parts of Canada, most of Europe, the Midwest and northeast region of the U.S., northern Australia, western Russia and parts of China.
The USask study of over 8,700 daily rain records from 100,000 stations monitoring rain worldwide found the frequency of torrential rain between 1964 and 2013 increased as the decades progressed.
Between 2004 and 2013, there were seven per cent more extreme bouts of heavy rain overall than expected globally. In Europe and Asia, there were 8.6 per cent more ‘extreme rain events’ overall, during this decade.
Global warming can lead to increased precipitation because more heat in the atmosphere leads to more atmospheric water which, in turn, leads to rain.
More than half a million deaths were caused by rain-induced floods between 1980 and 2009. Heavy rain can also cause landslides, damage crops, collapse buildings and bridges, wreck homes, and lead to chaos on roads and to transport, with huge financial losses.
Co-author Alberto Montanari, professor of hydraulic works and hydrology at the University of Bologna and president of the European Geoscience Union, said: “Our results are in line with the assumption that the atmosphere retains more water under global warming. The fact that the frequency, rather the magnitude, of extreme precipitation is significantly increasing has relevant implications for climate adaptation. Human systems need to increase their capability to react to frequent shocks.”
[Global Institute for Water Security at the University of Saskatchewan]